source: src/libcfa/concurrency/monitor.c@ c366ec6

ADT aaron-thesis arm-eh ast-experimental cleanup-dtors deferred_resn demangler enum forall-pointer-decay jacob/cs343-translation jenkins-sandbox new-ast new-ast-unique-expr new-env no_list persistent-indexer pthread-emulation qualifiedEnum resolv-new with_gc
Last change on this file since c366ec6 was 66298de, checked in by Thierry Delisle <tdelisle@…>, 8 years ago

Fixed uninitialized memory bug
  • Property mode set to 100644
File size: 27.7 KB
Line 
1//
2// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
3//
4// The contents of this file are covered under the licence agreement in the
5// file "LICENCE" distributed with Cforall.
6//
7// monitor_desc.c --
8//
9// Author : Thierry Delisle
10// Created On : Thd Feb 23 12:27:26 2017
11// Last Modified By : Peter A. Buhr
12// Last Modified On : Mon Jul 31 14:59:05 2017
13// Update Count : 3
14//
15
16#include "monitor"
17
18#include <stdlib>
19
20#include "libhdr.h"
21#include "kernel_private.h"
22
23//-----------------------------------------------------------------------------
24// Forward declarations
25static inline void set_owner ( monitor_desc * this, thread_desc * owner );
26static inline void set_owner ( monitor_desc ** storage, short count, thread_desc * owner );
27static inline void set_mask ( monitor_desc ** storage, short count, const __waitfor_mask_t & mask );
28static inline void reset_mask( monitor_desc * this );
29
30static inline thread_desc * next_thread( monitor_desc * this );
31static inline bool is_accepted( monitor_desc * this, const __monitor_group_t & monitors );
32
33static inline void lock_all( spinlock ** locks, unsigned short count );
34static inline void lock_all( monitor_desc ** source, spinlock ** /*out*/ locks, unsigned short count );
35static inline void unlock_all( spinlock ** locks, unsigned short count );
36static inline void unlock_all( monitor_desc ** locks, unsigned short count );
37
38static inline void save ( monitor_desc ** ctx, short count, spinlock ** locks, unsigned int * /*out*/ recursions, __waitfor_mask_t * /*out*/ masks );
39static inline void restore( monitor_desc ** ctx, short count, spinlock ** locks, unsigned int * /*in */ recursions, __waitfor_mask_t * /*in */ masks );
40
41static inline void init ( int count, monitor_desc ** monitors, __condition_node_t * waiter, __condition_criterion_t * criteria );
42static inline void init_push( int count, monitor_desc ** monitors, __condition_node_t * waiter, __condition_criterion_t * criteria );
43
44static inline thread_desc * check_condition ( __condition_criterion_t * );
45static inline void brand_condition ( condition * );
46static inline [thread_desc *, int] search_entry_queue( const __waitfor_mask_t &, monitor_desc ** monitors, int count );
47
48forall(dtype T | sized( T ))
49static inline short insert_unique( T ** array, short & size, T * val );
50static inline short count_max ( const __waitfor_mask_t & mask );
51static inline short aggregate ( monitor_desc ** storage, const __waitfor_mask_t & mask );
52
53//-----------------------------------------------------------------------------
54// Useful defines
55#define wait_ctx(thrd, user_info) /* Create the necessary information to use the signaller stack */ \
56 __condition_node_t waiter = { thrd, count, user_info }; /* Create the node specific to this wait operation */ \
57 __condition_criterion_t criteria[count]; /* Create the creteria this wait operation needs to wake up */ \
58 init( count, monitors, &waiter, criteria ); /* Link everything together */ \
59
60#define wait_ctx_primed(thrd, user_info) /* Create the necessary information to use the signaller stack */ \
61 __condition_node_t waiter = { thrd, count, user_info }; /* Create the node specific to this wait operation */ \
62 __condition_criterion_t criteria[count]; /* Create the creteria this wait operation needs to wake up */ \
63 init_push( count, monitors, &waiter, criteria ); /* Link everything together and push it to the AS-Stack */ \
64
65#define monitor_ctx( mons, cnt ) /* Define that create the necessary struct for internal/external scheduling operations */ \
66 monitor_desc ** monitors = mons; /* Save the targeted monitors */ \
67 unsigned short count = cnt; /* Save the count to a local variable */ \
68 unsigned int recursions[ count ]; /* Save the current recursion levels to restore them later */ \
69 __waitfor_mask_t masks[ count ]; /* Save the current waitfor masks to restore them later */ \
70 spinlock * locks [ count ]; /* We need to pass-in an array of locks to BlockInternal */ \
71
72#define monitor_save save ( monitors, count, locks, recursions, masks )
73#define monitor_restore restore( monitors, count, locks, recursions, masks )
74
75
76//-----------------------------------------------------------------------------
77// Enter/Leave routines
78
79
80extern "C" {
81 // Enter single monitor
82 static void __enter_monitor_desc( monitor_desc * this, const __monitor_group_t & group ) {
83 // Lock the monitor spinlock, lock_yield to reduce contention
84 lock_yield( &this->lock DEBUG_CTX2 );
85 thread_desc * thrd = this_thread;
86
87 LIB_DEBUG_PRINT_SAFE("Kernel : %10p Entering mon %p (%p)\n", thrd, this, this->owner);
88
89 if( !this->owner ) {
90 // No one has the monitor, just take it
91 set_owner( this, thrd );
92
93 LIB_DEBUG_PRINT_SAFE("Kernel : mon is free \n");
94 }
95 else if( this->owner == thrd) {
96 // We already have the monitor, just note how many times we took it
97 verify( this->recursion > 0 );
98 this->recursion += 1;
99
100 LIB_DEBUG_PRINT_SAFE("Kernel : mon already owned \n");
101 }
102 else if( is_accepted( this, group) ) {
103 // Some one was waiting for us, enter
104 set_owner( this, thrd );
105
106 // Reset mask
107 reset_mask( this );
108
109 LIB_DEBUG_PRINT_SAFE("Kernel : mon accepts \n");
110 }
111 else {
112 LIB_DEBUG_PRINT_SAFE("Kernel : blocking \n");
113
114 // Some one else has the monitor, wait in line for it
115 append( &this->entry_queue, thrd );
116 BlockInternal( &this->lock );
117
118 LIB_DEBUG_PRINT_SAFE("Kernel : %10p Entered mon %p\n", thrd, this);
119
120 // BlockInternal will unlock spinlock, no need to unlock ourselves
121 return;
122 }
123
124 LIB_DEBUG_PRINT_SAFE("Kernel : %10p Entered mon %p\n", thrd, this);
125
126 // Release the lock and leave
127 unlock( &this->lock );
128 return;
129 }
130
131 static void __enter_monitor_dtor( monitor_desc * this, fptr_t func ) {
132 // Lock the monitor spinlock, lock_yield to reduce contention
133 lock_yield( &this->lock DEBUG_CTX2 );
134 thread_desc * thrd = this_thread;
135
136 LIB_DEBUG_PRINT_SAFE("Kernel : %10p Entering dtor for mon %p (%p)\n", thrd, this, this->owner);
137
138
139 if( !this->owner ) {
140 LIB_DEBUG_PRINT_SAFE("Kernel : Destroying free mon %p\n", this);
141
142 // No one has the monitor, just take it
143 set_owner( this, thrd );
144
145 unlock( &this->lock );
146 return;
147 }
148 else if( this->owner == thrd) {
149 // We already have the monitor... but where about to destroy it so the nesting will fail
150 // Abort!
151 abortf("Attempt to destroy monitor %p by thread \"%.256s\" (%p) in nested mutex.");
152 }
153
154 int count = 1;
155 monitor_desc ** monitors = &this;
156 __monitor_group_t group = { &this, 1, func };
157 if( is_accepted( this, group) ) {
158 LIB_DEBUG_PRINT_SAFE("Kernel : mon accepts dtor, block and signal it \n");
159
160 // Wake the thread that is waiting for this
161 __condition_criterion_t * urgent = pop( &this->signal_stack );
162 verify( urgent );
163
164 // Reset mask
165 reset_mask( this );
166
167 // Create the node specific to this wait operation
168 wait_ctx_primed( this_thread, 0 )
169
170 // Some one else has the monitor, wait for him to finish and then run
171 BlockInternal( &this->lock, urgent->owner->waiting_thread );
172
173 // Some one was waiting for us, enter
174 set_owner( this, thrd );
175 }
176 else {
177 LIB_DEBUG_PRINT_SAFE("Kernel : blocking \n");
178
179 wait_ctx( this_thread, 0 )
180 this->dtor_node = &waiter;
181
182 // Some one else has the monitor, wait in line for it
183 append( &this->entry_queue, thrd );
184 BlockInternal( &this->lock );
185
186 // BlockInternal will unlock spinlock, no need to unlock ourselves
187 return;
188 }
189
190 LIB_DEBUG_PRINT_SAFE("Kernel : Destroying %p\n", this);
191
192 }
193
194 // Leave single monitor
195 void __leave_monitor_desc( monitor_desc * this ) {
196 // Lock the monitor spinlock, lock_yield to reduce contention
197 lock_yield( &this->lock DEBUG_CTX2 );
198
199 LIB_DEBUG_PRINT_SAFE("Kernel : %10p Leaving mon %p (%p)\n", this_thread, this, this->owner);
200
201 verifyf( this_thread == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", this_thread, this->owner, this->recursion, this );
202
203 // Leaving a recursion level, decrement the counter
204 this->recursion -= 1;
205
206 // If we haven't left the last level of recursion
207 // it means we don't need to do anything
208 if( this->recursion != 0) {
209 unlock( &this->lock );
210 return;
211 }
212
213 // Get the next thread, will be null on low contention monitor
214 thread_desc * new_owner = next_thread( this );
215
216 // We can now let other threads in safely
217 unlock( &this->lock );
218
219 //We need to wake-up the thread
220 WakeThread( new_owner );
221 }
222
223 // Leave single monitor for the last time
224 void __leave_dtor_monitor_desc( monitor_desc * this ) {
225 LIB_DEBUG_DO(
226 if( this_thread != this->owner ) {
227 abortf("Destroyed monitor %p has inconsistent owner, expected %p got %p.\n", this, this_thread, this->owner);
228 }
229 if( this->recursion != 1 ) {
230 abortf("Destroyed monitor %p has %d outstanding nested calls.\n", this, this->recursion - 1);
231 }
232 )
233 }
234
235 // Leave the thread monitor
236 // last routine called by a thread.
237 // Should never return
238 void __leave_thread_monitor( thread_desc * thrd ) {
239 monitor_desc * this = &thrd->self_mon;
240
241 // Lock the monitor now
242 lock_yield( &this->lock DEBUG_CTX2 );
243
244 disable_interrupts();
245
246 thrd->self_cor.state = Halted;
247
248 verifyf( thrd == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", thrd, this->owner, this->recursion, this );
249
250 // Leaving a recursion level, decrement the counter
251 this->recursion -= 1;
252
253 // If we haven't left the last level of recursion
254 // it must mean there is an error
255 if( this->recursion != 0) { abortf("Thread internal monitor has unbalanced recursion"); }
256
257 // Fetch the next thread, can be null
258 thread_desc * new_owner = next_thread( this );
259
260 // Leave the thread, this will unlock the spinlock
261 // Use leave thread instead of BlockInternal which is
262 // specialized for this case and supports null new_owner
263 LeaveThread( &this->lock, new_owner );
264
265 // Control flow should never reach here!
266 }
267}
268
269// Enter multiple monitor
270// relies on the monitor array being sorted
271static inline void enter( __monitor_group_t monitors ) {
272 for(int i = 0; i < monitors.size; i++) {
273 __enter_monitor_desc( monitors.list[i], monitors );
274 }
275}
276
277// Leave multiple monitor
278// relies on the monitor array being sorted
279static inline void leave(monitor_desc ** monitors, int count) {
280 for(int i = count - 1; i >= 0; i--) {
281 __leave_monitor_desc( monitors[i] );
282 }
283}
284
285// Ctor for monitor guard
286// Sorts monitors before entering
287void ?{}( monitor_guard_t & this, monitor_desc ** m, int count, fptr_t func ) {
288 // Store current array
289 this.m = m;
290 this.count = count;
291
292 // Sort monitors based on address -> TODO use a sort specialized for small numbers
293 qsort(this.m, count);
294
295 // Save previous thread context
296 this.prev_mntrs = this_thread->monitors.list;
297 this.prev_count = this_thread->monitors.size;
298 this.prev_func = this_thread->monitors.func;
299
300 // Update thread context (needed for conditions)
301 this_thread->monitors.list = m;
302 this_thread->monitors.size = count;
303 this_thread->monitors.func = func;
304
305 // LIB_DEBUG_PRINT_SAFE("MGUARD : enter %d\n", count);
306
307 // Enter the monitors in order
308 __monitor_group_t group = {this.m, this.count, func};
309 enter( group );
310
311 // LIB_DEBUG_PRINT_SAFE("MGUARD : entered\n");
312}
313
314
315// Dtor for monitor guard
316void ^?{}( monitor_guard_t & this ) {
317 // LIB_DEBUG_PRINT_SAFE("MGUARD : leaving %d\n", this.count);
318
319 // Leave the monitors in order
320 leave( this.m, this.count );
321
322 // LIB_DEBUG_PRINT_SAFE("MGUARD : left\n");
323
324 // Restore thread context
325 this_thread->monitors.list = this.prev_mntrs;
326 this_thread->monitors.size = this.prev_count;
327 this_thread->monitors.func = this.prev_func;
328}
329
330
331// Ctor for monitor guard
332// Sorts monitors before entering
333void ?{}( monitor_dtor_guard_t & this, monitor_desc ** m, fptr_t func ) {
334 // Store current array
335 this.m = *m;
336
337 // Save previous thread context
338 this.prev_mntrs = this_thread->monitors.list;
339 this.prev_count = this_thread->monitors.size;
340 this.prev_func = this_thread->monitors.func;
341
342 // Update thread context (needed for conditions)
343 this_thread->monitors.list = m;
344 this_thread->monitors.size = 1;
345 this_thread->monitors.func = func;
346
347 __enter_monitor_dtor( this.m, func );
348}
349
350
351// Dtor for monitor guard
352void ^?{}( monitor_dtor_guard_t & this ) {
353 // Leave the monitors in order
354 __leave_dtor_monitor_desc( this.m );
355
356 // Restore thread context
357 this_thread->monitors.list = this.prev_mntrs;
358 this_thread->monitors.size = this.prev_count;
359 this_thread->monitors.func = this.prev_func;
360}
361
362//-----------------------------------------------------------------------------
363// Internal scheduling types
364void ?{}(__condition_node_t & this, thread_desc * waiting_thread, unsigned short count, uintptr_t user_info ) {
365 this.waiting_thread = waiting_thread;
366 this.count = count;
367 this.next = NULL;
368 this.user_info = user_info;
369}
370
371void ?{}(__condition_criterion_t & this ) {
372 this.ready = false;
373 this.target = NULL;
374 this.owner = NULL;
375 this.next = NULL;
376}
377
378void ?{}(__condition_criterion_t & this, monitor_desc * target, __condition_node_t * owner ) {
379 this.ready = false;
380 this.target = target;
381 this.owner = owner;
382 this.next = NULL;
383}
384
385//-----------------------------------------------------------------------------
386// Internal scheduling
387void wait( condition * this, uintptr_t user_info = 0 ) {
388 brand_condition( this );
389
390 // Check that everything is as expected
391 assertf( this->monitors != NULL, "Waiting with no monitors (%p)", this->monitors );
392 verifyf( this->monitor_count != 0, "Waiting with 0 monitors (%i)", this->monitor_count );
393 verifyf( this->monitor_count < 32u, "Excessive monitor count (%i)", this->monitor_count );
394
395 // Create storage for monitor context
396 monitor_ctx( this->monitors, this->monitor_count );
397
398 // Create the node specific to this wait operation
399 wait_ctx( this_thread, user_info );
400
401 // Append the current wait operation to the ones already queued on the condition
402 // We don't need locks for that since conditions must always be waited on inside monitor mutual exclusion
403 append( &this->blocked, &waiter );
404
405 // Lock all monitors (aggregates the locks as well)
406 lock_all( monitors, locks, count );
407
408 // Find the next thread(s) to run
409 short thread_count = 0;
410 thread_desc * threads[ count ];
411 __builtin_memset( threads, 0, sizeof( threads ) );
412
413 // Save monitor states
414 monitor_save;
415
416 // Remove any duplicate threads
417 for( int i = 0; i < count; i++) {
418 thread_desc * new_owner = next_thread( monitors[i] );
419 insert_unique( threads, thread_count, new_owner );
420 }
421
422 // Everything is ready to go to sleep
423 BlockInternal( locks, count, threads, thread_count );
424
425 // We are back, restore the owners and recursions
426 monitor_restore;
427}
428
429bool signal( condition * this ) {
430 if( is_empty( this ) ) { return false; }
431
432 //Check that everything is as expected
433 verify( this->monitors );
434 verify( this->monitor_count != 0 );
435
436 //Some more checking in debug
437 LIB_DEBUG_DO(
438 thread_desc * this_thrd = this_thread;
439 if ( this->monitor_count != this_thrd->monitors.size ) {
440 abortf( "Signal on condition %p made with different number of monitor(s), expected %i got %i", this, this->monitor_count, this_thrd->monitors.size );
441 }
442
443 for(int i = 0; i < this->monitor_count; i++) {
444 if ( this->monitors[i] != this_thrd->monitors.list[i] ) {
445 abortf( "Signal on condition %p made with different monitor, expected %p got %i", this, this->monitors[i], this_thrd->monitors.list[i] );
446 }
447 }
448 );
449
450 unsigned short count = this->monitor_count;
451
452 // Lock all monitors
453 lock_all( this->monitors, NULL, count );
454
455 //Pop the head of the waiting queue
456 __condition_node_t * node = pop_head( &this->blocked );
457
458 //Add the thread to the proper AS stack
459 for(int i = 0; i < count; i++) {
460 __condition_criterion_t * crit = &node->criteria[i];
461 assert( !crit->ready );
462 push( &crit->target->signal_stack, crit );
463 }
464
465 //Release
466 unlock_all( this->monitors, count );
467
468 return true;
469}
470
471bool signal_block( condition * this ) {
472 if( !this->blocked.head ) { return false; }
473
474 //Check that everything is as expected
475 verifyf( this->monitors != NULL, "Waiting with no monitors (%p)", this->monitors );
476 verifyf( this->monitor_count != 0, "Waiting with 0 monitors (%i)", this->monitor_count );
477
478 // Create storage for monitor context
479 monitor_ctx( this->monitors, this->monitor_count );
480
481 // Lock all monitors (aggregates the locks them as well)
482 lock_all( monitors, locks, count );
483
484 // Create the node specific to this wait operation
485 wait_ctx_primed( this_thread, 0 )
486
487 //save contexts
488 monitor_save;
489
490 //Find the thread to run
491 thread_desc * signallee = pop_head( &this->blocked )->waiting_thread;
492 set_owner( monitors, count, signallee );
493
494 //Everything is ready to go to sleep
495 BlockInternal( locks, count, &signallee, 1 );
496
497
498 // WE WOKE UP
499
500
501 //We are back, restore the masks and recursions
502 monitor_restore;
503
504 return true;
505}
506
507// Access the user_info of the thread waiting at the front of the queue
508uintptr_t front( condition * this ) {
509 verifyf( !is_empty(this),
510 "Attempt to access user data on an empty condition.\n"
511 "Possible cause is not checking if the condition is empty before reading stored data."
512 );
513 return this->blocked.head->user_info;
514}
515
516//-----------------------------------------------------------------------------
517// External scheduling
518// cases to handle :
519// - target already there :
520// block and wake
521// - dtor already there
522// put thread on signaller stack
523// - non-blocking
524// return else
525// - timeout
526// return timeout
527// - block
528// setup mask
529// block
530void __waitfor_internal( const __waitfor_mask_t & mask, int duration ) {
531 // This statment doesn't have a contiguous list of monitors...
532 // Create one!
533 short max = count_max( mask );
534 monitor_desc * mon_storage[max];
535 __builtin_memset( mon_storage, 0, sizeof( mon_storage ) );
536 short actual_count = aggregate( mon_storage, mask );
537
538 LIB_DEBUG_PRINT_SAFE("Kernel : waitfor %d (s: %d, m: %d)\n", actual_count, mask.size, (short)max);
539
540 if(actual_count == 0) return;
541
542 LIB_DEBUG_PRINT_SAFE("Kernel : waitfor internal proceeding\n");
543
544 // Create storage for monitor context
545 monitor_ctx( mon_storage, actual_count );
546
547 // Lock all monitors (aggregates the locks as well)
548 lock_all( monitors, locks, count );
549
550 {
551 // Check if the entry queue
552 thread_desc * next; int index;
553 [next, index] = search_entry_queue( mask, monitors, count );
554
555 if( next ) {
556 *mask.accepted = index;
557 if( mask.clauses[index].is_dtor ) {
558 LIB_DEBUG_PRINT_SAFE("Kernel : dtor already there\n");
559 verifyf( mask.clauses[index].size == 1 , "ERROR: Accepted dtor has more than 1 mutex parameter." );
560
561 monitor_desc * mon2dtor = mask.clauses[index].list[0];
562 verifyf( mon2dtor->dtor_node, "ERROR: Accepted monitor has no dtor_node." );
563
564 __condition_criterion_t * dtor_crit = mon2dtor->dtor_node->criteria;
565 push( &mon2dtor->signal_stack, dtor_crit );
566
567 unlock_all( locks, count );
568 }
569 else {
570 LIB_DEBUG_PRINT_SAFE("Kernel : thread present, baton-passing\n");
571
572 // Create the node specific to this wait operation
573 wait_ctx_primed( this_thread, 0 );
574
575 // Save monitor states
576 monitor_save;
577
578 // Set the owners to be the next thread
579 set_owner( monitors, count, next );
580
581 // Everything is ready to go to sleep
582 BlockInternal( locks, count, &next, 1 );
583
584 // We are back, restore the owners and recursions
585 monitor_restore;
586
587 LIB_DEBUG_PRINT_SAFE("Kernel : thread present, returned\n");
588 }
589
590 LIB_DEBUG_PRINT_SAFE("Kernel : accepted %d\n", *mask.accepted);
591
592 return;
593 }
594 }
595
596
597 if( duration == 0 ) {
598 LIB_DEBUG_PRINT_SAFE("Kernel : non-blocking, exiting\n");
599
600 unlock_all( locks, count );
601
602 LIB_DEBUG_PRINT_SAFE("Kernel : accepted %d\n", *mask.accepted);
603 return;
604 }
605
606
607 verifyf( duration < 0, "Timeout on waitfor statments not supported yet.");
608
609 LIB_DEBUG_PRINT_SAFE("Kernel : blocking waitfor\n");
610
611 // Create the node specific to this wait operation
612 wait_ctx_primed( this_thread, 0 );
613
614 monitor_save;
615 set_mask( monitors, count, mask );
616
617 for(int i = 0; i < count; i++) {
618 verify( monitors[i]->owner == this_thread );
619 }
620
621 //Everything is ready to go to sleep
622 BlockInternal( locks, count );
623
624
625 // WE WOKE UP
626
627
628 //We are back, restore the masks and recursions
629 monitor_restore;
630
631 LIB_DEBUG_PRINT_SAFE("Kernel : exiting\n");
632
633 LIB_DEBUG_PRINT_SAFE("Kernel : accepted %d\n", *mask.accepted);
634}
635
636//-----------------------------------------------------------------------------
637// Utilities
638
639static inline void set_owner( monitor_desc * this, thread_desc * owner ) {
640 // LIB_DEBUG_PRINT_SAFE("Kernal : Setting owner of %p to %p ( was %p)\n", this, owner, this->owner );
641
642 //Pass the monitor appropriately
643 this->owner = owner;
644
645 //We are passing the monitor to someone else, which means recursion level is not 0
646 this->recursion = owner ? 1 : 0;
647}
648
649static inline void set_owner( monitor_desc ** monitors, short count, thread_desc * owner ) {
650 for( int i = 0; i < count; i++ ) {
651 set_owner( monitors[i], owner );
652 }
653}
654
655static inline void set_mask( monitor_desc ** storage, short count, const __waitfor_mask_t & mask ) {
656 for(int i = 0; i < count; i++) {
657 storage[i]->mask = mask;
658 }
659}
660
661static inline void reset_mask( monitor_desc * this ) {
662 this->mask.accepted = NULL;
663 this->mask.clauses = NULL;
664 this->mask.size = 0;
665}
666
667static inline thread_desc * next_thread( monitor_desc * this ) {
668 //Check the signaller stack
669 __condition_criterion_t * urgent = pop( &this->signal_stack );
670 if( urgent ) {
671 //The signaller stack is not empty,
672 //regardless of if we are ready to baton pass,
673 //we need to set the monitor as in use
674 set_owner( this, urgent->owner->waiting_thread );
675
676 return check_condition( urgent );
677 }
678
679 // No signaller thread
680 // Get the next thread in the entry_queue
681 thread_desc * new_owner = pop_head( &this->entry_queue );
682 set_owner( this, new_owner );
683
684 return new_owner;
685}
686
687static inline bool is_accepted( monitor_desc * this, const __monitor_group_t & group ) {
688 __acceptable_t * it = this->mask.clauses; // Optim
689 int count = this->mask.size;
690
691 // Check if there are any acceptable functions
692 if( !it ) return false;
693
694 // If this isn't the first monitor to test this, there is no reason to repeat the test.
695 if( this != group[0] ) return group[0]->mask.accepted >= 0;
696
697 // For all acceptable functions check if this is the current function.
698 for( short i = 0; i < count; i++, it++ ) {
699 if( *it == group ) {
700 *this->mask.accepted = i;
701 return true;
702 }
703 }
704
705 // No function matched
706 return false;
707}
708
709static inline void init( int count, monitor_desc ** monitors, __condition_node_t * waiter, __condition_criterion_t * criteria ) {
710 for(int i = 0; i < count; i++) {
711 (criteria[i]){ monitors[i], waiter };
712 }
713
714 waiter->criteria = criteria;
715}
716
717static inline void init_push( int count, monitor_desc ** monitors, __condition_node_t * waiter, __condition_criterion_t * criteria ) {
718 for(int i = 0; i < count; i++) {
719 (criteria[i]){ monitors[i], waiter };
720 push( &criteria[i].target->signal_stack, &criteria[i] );
721 }
722
723 waiter->criteria = criteria;
724}
725
726static inline void lock_all( spinlock ** locks, unsigned short count ) {
727 for( int i = 0; i < count; i++ ) {
728 lock_yield( locks[i] DEBUG_CTX2 );
729 }
730}
731
732static inline void lock_all( monitor_desc ** source, spinlock ** /*out*/ locks, unsigned short count ) {
733 for( int i = 0; i < count; i++ ) {
734 spinlock * l = &source[i]->lock;
735 lock_yield( l DEBUG_CTX2 );
736 if(locks) locks[i] = l;
737 }
738}
739
740static inline void unlock_all( spinlock ** locks, unsigned short count ) {
741 for( int i = 0; i < count; i++ ) {
742 unlock( locks[i] );
743 }
744}
745
746static inline void unlock_all( monitor_desc ** locks, unsigned short count ) {
747 for( int i = 0; i < count; i++ ) {
748 unlock( &locks[i]->lock );
749 }
750}
751
752static inline void save( monitor_desc ** ctx, short count, __attribute((unused)) spinlock ** locks, unsigned int * /*out*/ recursions, __waitfor_mask_t * /*out*/ masks ) {
753 for( int i = 0; i < count; i++ ) {
754 recursions[i] = ctx[i]->recursion;
755 masks[i] = ctx[i]->mask;
756 }
757}
758
759static inline void restore( monitor_desc ** ctx, short count, spinlock ** locks, unsigned int * /*out*/ recursions, __waitfor_mask_t * /*out*/ masks ) {
760 lock_all( locks, count );
761 for( int i = 0; i < count; i++ ) {
762 ctx[i]->recursion = recursions[i];
763 ctx[i]->mask = masks[i];
764 }
765 unlock_all( locks, count );
766}
767
768// Function has 2 different behavior
769// 1 - Marks a monitors as being ready to run
770// 2 - Checks if all the monitors are ready to run
771// if so return the thread to run
772static inline thread_desc * check_condition( __condition_criterion_t * target ) {
773 __condition_node_t * node = target->owner;
774 unsigned short count = node->count;
775 __condition_criterion_t * criteria = node->criteria;
776
777 bool ready2run = true;
778
779 for( int i = 0; i < count; i++ ) {
780
781 // LIB_DEBUG_PRINT_SAFE( "Checking %p for %p\n", &criteria[i], target );
782 if( &criteria[i] == target ) {
783 criteria[i].ready = true;
784 // LIB_DEBUG_PRINT_SAFE( "True\n" );
785 }
786
787 ready2run = criteria[i].ready && ready2run;
788 }
789
790 // LIB_DEBUG_PRINT_SAFE( "Runing %i\n", ready2run );
791 return ready2run ? node->waiting_thread : NULL;
792}
793
794static inline void brand_condition( condition * this ) {
795 thread_desc * thrd = this_thread;
796 if( !this->monitors ) {
797 // LIB_DEBUG_PRINT_SAFE("Branding\n");
798 assertf( thrd->monitors.list != NULL, "No current monitor to brand condition %p", thrd->monitors.list );
799 this->monitor_count = thrd->monitors.size;
800
801 this->monitors = malloc( this->monitor_count * sizeof( *this->monitors ) );
802 for( int i = 0; i < this->monitor_count; i++ ) {
803 this->monitors[i] = thrd->monitors.list[i];
804 }
805 }
806}
807
808static inline [thread_desc *, int] search_entry_queue( const __waitfor_mask_t & mask, monitor_desc ** monitors, int count ) {
809
810 __thread_queue_t * entry_queue = &monitors[0]->entry_queue;
811
812 // For each thread in the entry-queue
813 for( thread_desc ** thrd_it = &entry_queue->head;
814 *thrd_it;
815 thrd_it = &(*thrd_it)->next
816 ) {
817 // For each acceptable check if it matches
818 int i = 0;
819 __acceptable_t * end = mask.clauses + mask.size;
820 for( __acceptable_t * it = mask.clauses; it != end; it++, i++ ) {
821 // Check if we have a match
822 if( *it == (*thrd_it)->monitors ) {
823
824 // If we have a match return it
825 // after removeing it from the entry queue
826 return [remove( entry_queue, thrd_it ), i];
827 }
828 }
829 }
830
831 return [0, -1];
832}
833
834forall(dtype T | sized( T ))
835static inline short insert_unique( T ** array, short & size, T * val ) {
836 if( !val ) return size;
837
838 for(int i = 0; i <= size; i++) {
839 if( array[i] == val ) return size;
840 }
841
842 array[size] = val;
843 size = size + 1;
844 return size;
845}
846
847static inline short count_max( const __waitfor_mask_t & mask ) {
848 short max = 0;
849 for( int i = 0; i < mask.size; i++ ) {
850 max += mask.clauses[i].size;
851 }
852 return max;
853}
854
855static inline short aggregate( monitor_desc ** storage, const __waitfor_mask_t & mask ) {
856 short size = 0;
857 for( int i = 0; i < mask.size; i++ ) {
858 for( int j = 0; j < mask.clauses[i].size; j++) {
859 insert_unique( storage, size, mask.clauses[i].list[j] );
860 }
861 }
862 qsort( storage, size );
863 return size;
864}
865
866void ?{}( __condition_blocked_queue_t & this ) {
867 this.head = NULL;
868 this.tail = &this.head;
869}
870
871void append( __condition_blocked_queue_t * this, __condition_node_t * c ) {
872 verify(this->tail != NULL);
873 *this->tail = c;
874 this->tail = &c->next;
875}
876
877__condition_node_t * pop_head( __condition_blocked_queue_t * this ) {
878 __condition_node_t * head = this->head;
879 if( head ) {
880 this->head = head->next;
881 if( !head->next ) {
882 this->tail = &this->head;
883 }
884 head->next = NULL;
885 }
886 return head;
887}
888
889// Local Variables: //
890// mode: c //
891// tab-width: 4 //
892// End: //
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